Build libSwiftStaticMirror as a standalone library with minimal required dependencies.

This separates it from `libSwiftScan` and allows us to build this library without building much of the rest of the compiler.

Also refactor `utils/build-parser-lib` into `utils/build-tooling-libs` which builds both SwiftSyntaxParser and SwiftStaticMirror.

lib/DependencyScan/ScanDependencies.cpp

@@ -47,6 +47,7 @@
 
 using namespace swift;
 using namespace swift::dependencies;
+using namespace swift::c_string_utils;
 using namespace llvm::yaml;
 
 namespace {